Endoscope stopcock with a detent device

ABSTRACT

A stopcock controlling ducts in medical endoscopes passing flux media, comprising a housing made of a hard material and rotatably receiving a conical plug in a conical seat crossed by a duct, said housing subtending in the direction of the axis of rotation and beyond the larger opening of the conical seat a bearing collar which supports a rotary body that is rotatable about the axis of rotation, said rotary body being fitted outside said housing with a handle and being rotationally coupled with the plug and axially displaceable and being biased by a-spring relative to said plug and further being fitted with a radially elastic detent device which in the assembled state of said stopcock is configured inside the housing, said rotary body by means of said detent device acting in locking manner against the spring action on said bearing collar, characterized in that the rotary body is fitted with prefabricated rupture site which following deliberate rupture shall expose the snap-in device.

[0001] The invention relates to a stopcock of the kind defined in thepreamble of claim 1.

[0002] Stopcocks on endoscopes control flux media such as gas orirrigation liquids flowing through ducts in the endoscope. In earlierdesigns, the plug is secured by a screw on the stopcock housing.

[0003] The German patent document 198 19 814 C1 discloses a design ofthis kind. The stopcock housing is made of metal. and permanentlyaffixed to the endoscope, for instance by welding. To take care offriction and assure sealing, the plug is made of an appropriate plastic.The rotary body together with its handle also is made of plastic and bymeans of a detent device snaps into the housing, as a result of whichassembly is facilitated and manufacture more economical with respect toearlier designs comprising screw connections.

[0004] Because the detent device seated on the rotary body shall beconfigured within the housing when assembled, it shall be unaccessiblefollowing appropriate snap-in insertion and henceforth also-shall beundetachable. In case defects arise in the stopcock, especially when theconical element has suffered wear, the stopcock must be exchanged as awhole, and the entailed repair is unusually elaborate.

[0005] The object of the present invention is to create a stopcock ofthe initially cited kind that shall allow simpler and more economicalrepairs.

[0006] This goal is attained by the features of claim 1.

[0007] In the design of the invention, the rotary body comprises aprefabricated rupture site which after being deliberately ruptured willallow access to the detent device. To undertake repairs, thepredetermined rupture site is broken by forcing said rotary body'shandle. Thereupon the detent device is accessible and it may be unlockedusing an appropriate tool. Next the remainder of the rotary bodytogether with the detent element, the spring and plug, may be removedand replaced by new parts. During this procedure the stopcock housingmay remain on the endoscope while the elaborate steps heretoforerequired to change the housing now are eliminated.

[0008] The detent device may be designed in the manner of the citedGerman patent document 198 19 814 C1. However the features of claim 2are advantageous instead. According to claim 2, the detent device is asnap ring within a circumferential groove of the rotary body, saidcircumferential groove being deep enough to act as the prefabricatedrupture site. The functions of this design are therefore attained invery simple manner.

[0009] The invention is illustratively and schematically shown in theattached drawing of a cross-section of the stopcock of the invention.

[0010] The shown stopcock comprises a housing 1 which is crossed by aduct 2. This duct 2 crosses a conical seat 3 receiving a rotary conicalplug 4. The housing 1 is made of a hard material, preferably a metal.The conical plug 4 is made of a softer material, preferably anappropriate plastic.

[0011] Seen in the axial direction of the conical seat 3 and beyond thelarger opening of this conical seat, the housing 1 constitutes a tubularwall 5 which at its end away from the conical seat 3 tapers into anannular bearing collar 6. In the direction toward the conical seat 3,the bearing collar 6 constitutes an annular stop edge 7. The bearingcollar 6 is fitted with an insertion bevel 8 facing the outside.

[0012] A rotary body 9 also made of plastic and of appropriateproperties and moderately mechanically yielding is braced in the shownassembled position within the bearing collar 6 and is rotatable aboutthe axis of the conical seat 3. The rotary body 9 is fitted at its endaway from the housing 1 with an asymmetrical handle 10 used forrotation.

[0013] At its end facing the conical plug 4, the rotary body 9 comprisesa transverse groove 11 entered by two protrusions 12 affixed on that endsurface of the conical plug 4 which faces the rotary body 9. As shown bythe drawing, the protrusions 12 allow some longitudinal shift toward theaxis of rotation between the conical plug 4 and the rotary body 9, whilenevertheless securing the rotational connection between these two parts.The longitudinally displaceable rotational coupling of these two partsalso may be implemented in another manner, illustratively the transversegroove being fitted into the plug and the protrusions being configuredat the rotary body.

[0014] A blind borehole 13 situated in the axis of rotation is fittedinto the rotary body 9 from its end surface opposite the conical plug 4and receives a helical spring 14 resting on one hand on the bottom ofthe blind bore 13 and on the other hand on the end surface of theconical plug 4.

[0015] In the shown assembled configuration, a circumferential groove 15of appropriate depth in the rotary body 9 and situated at the level ofthe stop edge 7 of the bearing collar 6 receives and holds a snap ring16.

[0016] The assembly of the shown design is attained by first insertingthe conical plug 4 into the housing 1 open at the top. Thereupon therotary body 9 together with the snap ring 16 and helical spring 14 shallbe axially pressed into the housing at an appropriate rotationalposition allowing the protrusions 12 to enter the transverse groove 11.In the process, the snap ring 16—which unstressed is larger than thecircumference of the rotary body 9—is resiliently compressed at theinsertion bevel 8, and, once it has moved past the bearing collar 6,shall expand behind the stop edge 7. The rotary body 9, now beingrotationally coupled to the conical plug 4, is rotationally supported inthe housing 1 and is kept in the locked position in this housing whilebeing biased by the helical spring 14.

[0017] As shown, the detent device in the form of the shown snap ring 16now is located inside the tubular wall 5 of the housing 1 and henceshall be inaccessible from the outside.

[0018] If the shown stopcock must be disassembled, then the housing 1 onone hand and the handle 10 on the other shall be actuated and forceshall be applied to the rotary body 9 which thereby shall be broken offthe assembly at its prefabricated rupture site constituted by thecircumferential groove 15. Henceforth the detent device embodied in thesnap ring 16 is easily accessible from the outside and may be detachedusing a suitable tool such as snap-ring tongs. The remaining partsinside the housing may be removed through the opening of the housing 1at the bearing collar 6 and be replaced with new parts in relation tothe above discussed assembly procedure.

[0019] The prefabricated rupture site may also assume other forms.Instead of the shown annular groove 15, the rotary body 9 also may beweakened in other ways. For instance said rupture site may beconstituted by adjoining parts connected at their junction by aconnecting means subsequently easily torn off.

[0020] As regards other, similar embodiments of the stopcock such asdisclosed in the German patent document 19819814C1, other sites alsoprepared fora rupture exposing the locking device may be provided in therotary body to facilitate disassembly.

1. A stopcock controlling ducts in medical endoscopes passing fluxmedia, comprising a housing (1) made of a hard material and rotatablyreceiving a conical plug (4) in a conical seat (3) crossed by a duct(2), said housing subtending in the direction of the axis of rotationand beyond the larger opening of the conical seat (3) a bearing collar(6) which supports a rotary body (9) that is rotatable about the axis ofrotation, said rotary body being fitted outside said housing with ahandle (10) and being rotationally coupled with the plug and axiallydisplaceable and being biased by a spring relative to said plug andfurther being fitted with a radially elastic detent device (16) which inthe assembled state of said stopcock is configured inside the housing,said rotary body (9) by means of said detent device (16) acting inlocking manner against the spring action on said bearing collar (6),characterized in that the rotary body (9) is fitted with prefabricatedrupture site (15) which following deliberate rupture shall expose thedetent device (16).
 2. Stopcock as claimed in claim 1, characterized inthat the prefabricated rupture site assumes the form of acircumferential groove (15) holding a detent device in the form of asnap ring (16).